1. Field of the Invention
The present invention relates to a technology for producing a color filter for a color liquid crystal display adapted for use in a color television, a personal computer or the like, and more particularly to a method and an apparatus for producing a color filter by arranging plural colored filter elements on an optically translucent substrate, the color filter, a liquid crystal display device and an apparatus having such liquid crystal display device.
2. Related Background Art
For producing the color filter, there are conventionally known the dyeing method, the pigment dispersion method, the electro-deposition method, the printing method etc.
The dyeing method prepares the color filter by forming a layer of a water-soluble polymer material, for dyeing, on a glass substrate, forming the above-mentioned material into a desired pattern by a photolithographic process, then immersing the glass substrate into a dyeing bath to obtain a colored pattern, and repeating this process three times for red, green and blue colors.
The pigment dispersion method prepares the color filter by forming a layer of photosensitive resin, in which pigment is dispersed, on a glass substrate, then patterning the resin layer to obtain a mono-colored pattern and repeating this process three times for red, green and blue colors.
The electrodeposition method prepares the color filter by forming a transparent electrode pattern on a glass substrate, then immersing the glass substrate in an electrodeposition liquid containing pigment, resin, electrolyte etc. for depositing a single color, and repeating this process three times for red, green and blue colors.
The printing method prepares the color filter by printing thermosetting resin, containing dispersed pigment, three times respectively for red, green and blue colors and then thermally setting the resin.
These four methods in common require repetition of a same process by three times for forming red, green and blue colors, and such large number of steps reduces the production yield and increases the cost.
Besides, the electrodeposition method is hardly applicable to the TFT liquid crystal display since the formable pattern is limited in shape. Also the printing method is limited in resolution and cannot therefore be applied to finer patterns.
In order to resolve these drawbacks, there is proposed a method of forming the filter pattern by ink jet emission onto the glass substrate, as disclosed in the Japanese Patent Laid-Open Application Nos. 59-75205, 63-235901, 1-217320 etc.